Pump



2 Sheets-Sheet l Dec. 3, 1940. T. v. DILLSTRM PUMP Filed Aug. 10, 1938 Patented Dec. 3, 1940 UNITED STATES PATENT OFFICE PUMP Application August 1938, Serial No. 224,214 In Sweden September 28, 1937 13 Claims.` (Cl. 12S-139) The present invention relates to plunger pumps and has particular reference to plunger pumps particularly adapted to deliver liquid fuel under pressure for injection to different cylinders of an internal combustion engine. Still more particularly the invention relates to pumps of theo above character from which fuel is separately delivered to different pump outlets from a common pump chamber at different times during one 10 delivery stroke of the pump plunger.

In the operation of internal combustion engines to which fuel is injected it is frequently desirable, when the engine is operating at low load or no load, to operate on less than the total number of cylinders, cutting out certain of the cylinders in order that remaining cylinders may be operated under more favorable combustion conditions than if the small amount of fuel required to carry the low or idling load were distributed between all of the cylinders of the engine.

The present invention has for its general object the provision of an improved forni of r plunger pump construction of the kind in which 2 a plurality of pump outlets are supplied with fuel from a common pump cylinder at different times during one delivery stroke of the pump plunger, and in which the delivery of liquid to ,m one or more of the pump outlets may be cut out at will, without affecting the delivery of liquid to others of said outlets. Other and more detailed objects of the invention and the manner in which it may be carried into effect will best be understood from a consideration of the ensuing portion of this specification in which several practical examples of pump construction embodying the invention are described by way of illustration. reference being had to the accompanyingdrawings, in which;

Fig. l ts a central section of a pump embodying the invention and adapted to supply liquid to four outlets from a single pump cylinder;

Fig. 2, is .a section taken on the line 2-2 of Fig. 2; f Y

Fig. d is a developed view showing the cylinder and plunger porting of the pump illustrated 50 .in the preceding .r1

Fig.. 5 is a more or less diagrammatic view illustrating apptus suitable for effecting cut out of some of the outlets of the pump shown in Fig.. l.:

.l lr; o is a fraeutary section illustrating the 3 is a view taken onthe line 3-3 of variation of a part of the pump construction shown in Fig. l:

Fig. 'l is a fragmentary section showing a control valve of Fig. 6 in a different position; Fig. 8 is a more or less diagrammatic sectional view illustrating still another variation of structure for effecting the cut out of certain of the pump outlets; and

Fig. 9 is a fragmentary section showing the valve of Fig.' 8 in another position. 10

Referring now to Figs. 1 to 4, the pump illustrated comprises a main casing part I8 and a head part I2. A pump cylinder I4 is secured to part I2 by means of a suitable threaded collar I6 and a plunger I8 is reciprocably and tiun- 15 ably mounted in the bore of the pump cylinder. Pump chamber 20 is provided at the inner end `oi the plunger and liquid is drawn into this chamber through the suction line 22 under con trol of the spring loaded suction valve 2l. 20

Plunger I8 has a foot I8a at its outer end which rests against the bottom of a cylindrical recess formed in the upper portion of a tappet 26 slidably mounted in the casing part I8 and having a roller 28 contacting the face of cam 25 30. The cam is carried by a cam shaft 82 mounted in suitable bearings M in the pump casing.

An arcuate sector 38 mounted for turning movement in the pump casing around the tappet is provided with external teeth 38 located to en- 30 gage teeth on a rack 40 slidably mounted in the casing and adapted to be actuated by any sultable control (not shown). ,Tappet 28 is prevented from turning in the casing by means of locating pin 42 iixed in the pump casing and 35 at its inner end engaging a vertical slot 44 inthe wall of the tappet. The pump plunger is caused to turn with the sector 88. when the position of rack 48 is shifted. by means of the pin 46 fixed at one end in the foot I8a of the plunger 4o and extending through an arcuate slot 48 in the wall of the tappetto engage a vertical slot It formed in the sector 38.

rl'he pump spring 52 is compressed between the pump cylinder or barrel Il and a Spring retaining washer 54 seating against the tappet and serving also to engage the foot of the pump plunger to retain it in contact with the tappet. Spring 52 operates to cause the pump plunger and tappet to follow a path of reciprocation determined by the proile of cam 88.

The pump cylinder is provided with a series of delivery ports d1, dz, ds. and da leach located at a different height in the pump cylinder. 'me ports are conveniently disposed in two axial 55 planes at 90 with respect to each other, as shown in Figs. 1, 2 and 3, but other dispositions of the ports peripherally of the bore may be employed. Ports zii-d4 communicate respectively with delivery passages 56, 58, .80 and 82, which in turn communicate respectively with pump outlets 84, 86, 88 and l0, which as will be observed from Figs. 1 and 2, are advantageously distributed symmetrically around the central inlet 22. Each of the delivery passages communicates with its respective pump outlet through a spring loaded delivery valve `.712 all of which valves are designated by the same reference character.

In order to provide for the 'location of the delivery ports in the two axial planes indicated in Figs. 1 and 2, while at the same time having the symmetrical distribution of the outlets, the portions of the delivery passages 60a and @2a in the pump cylinder, with which ports da and d4 communicate respectively, are brought into communication respectively with the passages t@ and 82 in the head of the pump by the respective connections @b and 62h formed in the upper face of the pump barrel, as will be seen more clearly from Fig. 3.

As will be observed from Fig. 2, a series of relief or overflow ports r1, r2, r3 and r4 are arranged in vertical augment in the pump cylinder, there being one overflow port at the same level in the pump barrel as that of each delivery port. These relief ports communicate through suitable transverse channels with a common relief or overow passage 'id which, in the ernbodiment shown, delivers to a main overow it. Conveniently, the line of overflow ports is in the same axial plane as the delivery ports da, d4; port rz being directly opposite d2 and port r4 being directly opposite port d4.

The' pump cylinder is further provided with additional overiiow ports which may be conveniently termed auxiliary overilow ports. In the present embodiment two such ports arel shown at ai and a2 in Fig. 1 and these ports are con- 45 veniently located in the same axial plane with and opposite delivery ports di and da. Ports a1 and a2 communicate through suitable transverse channels with a common auxiliary overflow passage 'l8 leading to the auxiliary overflow 8@ by way of an auxiliary overflow control valve 82 which in the embodimentillustrated is in the form of a plug-type valve adapted to be turned to open or close the auxiliary overflow passage 18.

Intermediate its ends the plunger i8 is p rovided with a circumferentially extending recess 84 which is constantly in communication with the pump chamber 28 by way of passage 88 in the plunger. An island-like control projection 88, the outer surface of which is in contact with the wall oi the cylinder bore, is provided with an inclined control edge 90.

As will be seen from the developed view in Fig. 4, certain portions of the recess 84, indicated at 92, provide what may conveniently be termed plunger overow ports which are in line with the rows of cylinder delivery ports di, da and dz. d4, respectively. Channels formed between the upper and lower edges of the projection 88 and the upper and lower edges respectively ci.' the recess 84, provide at 94 and 96 two axially spaced ports in line with the row of main overow ports ri-n. The ports 94 and 96 may conveniently be considered as plunger overiiow ports. The recess 84 further provides an auxiliary plunger overiiow port, constituting that portion of the recess which is in line with the row of auxiliary overow ports -a1 and a2.

The operation of the pump above described is as follows; assuming valve 82 to be closed as indicated in Fig. l, and it further being assumed that the pump chamber is full of liquid and the plunger ascending on its delivery stroke. In the position of the plunger shown in Fig 4, delivery port di and auxiliary overflow port ai are both in communication with the plunger recess and the plunger overflow port 9&3 is in communcation with the overilow port r1. As the plunger ascends from this position, delivery through port di will not taire place until port 963 passes out of communication with port r1, whereupon delivery through port d1 will commence since flow through port ai is blocked by valve 82. The delivery period through port di, which may constitute an injection period to a fuel injector, continues until port 9% comes into registry with port r1 to terminate delivery ilcw through port d1. By the time this occurs, the plunger delivery port is in communication with port d2 and before port 96 passes out of communication with port r1, port 9d is in communication with port r2 to permit continuous overflow from the pump cylinder during the period between the time when delivery through port d1 is cut 01T by registry of port 96 with port r1 and the time when delivery through port d2 is established by port 9&3 passing above and out of communication with port r2, port @t having previously passed port r1. The above cycle of events takes place sequentially with respect todelivery through ports d3 and d4 as the plunger completes its delivery stroke, and, as was the case when delivery took place through port di, delivery through port da will take place in spite of communication between the plunger recess and the auxiliary overflow port a2, because of the fact of valve 82 being closed.

If now for any reason such as idling engine operation, it is desired to deliver through less than the total number of pump outlets, valve 92 is opened and by reference to Fig. 4 it will be apparent that with this valve open, delivery through ports di and da will not take place, since when the corresponding normal overflow ports Ti and r3 are covered by the control projection 88, overflow Will take place through port a1, or port a2 as the case may be, during the period when the plunger overflow portl is passing port di or port da.

It will be apparent that the number and sequence of the delivery outlets that may be put outof action through the medium of the auxiliary overflow may be varied as desired by varying the number and longitudinal location of the auxiliary overow ports. Ordinarily, when a pump of this kind is utilized as a fuel injection pump for an internal combustion engine, half the total number of pump outlets are arranged to be selectively put out of action by the auxiliary overflow ports and the auxiliary overflow ports are advantageously arranged as shown to put alternating delivery outlets out of action in order to provide equal time intervals between the remaining delivery periods.

In the drawings the pump plunger has been shown in the position of rotation corresponding to full load operation giving the maximum length of injection period through the ports through which delivery Ais effected. From inspection of Fig. 4 it will be apparent that if the plunger is turned so as to shift the control projection to the right as viewed in this figure, to bring the control edge 90 in line with the overflow ports n n,

the period of injection through each delivery port will be shortened. It will further be apparent that whether the plunger is in a position of rotation to eiect either full or part load delivery through the various delivery ports, opening of the auxiliary overow passage will have no effect on the length of the delivery periods determined by the position of rotation of the plunger and effected through the outlets which are not put out of action by the auxiliary overiiow.

While for convenience of illustration, in order to bring the various cylinder ports into the planes of the several sections, these ports have been shown as distributed 90 apart around the circumference of the cylinder bore, from inspection of Fig. 4 it will be evident that ports (Z1- d4 and ports a1, a2 may be placed in'any desired relation peripherally of the cylinder bore so long as they are peripherally displaced from the path of travel of the control projection 88 which cooperates with the line of overflow ports ri-r-i. In some instances it may be desirable to space the cylinder delivery. ports and the auxiliary overow ports so as to provide a greater peripheral distance for turning movement of the control projection, without interference with these ports, than is possible with the port distribution shown in Fig. 4.

Referring now to Fig. 5, there is illustrated more or less diagrammatically a convenient means for actuating the auxiliary overflow valve82 to automatically cut certain cylinders of an engine out of action under predetermined engine operating conditions. In this figure the engine is indicated at |00, the air intake being indicated at |02; Control of the output of the engine is eiected by means of the throttle valve |04 which 40 through the control rod |06 may be operated manually, by governor, y.or in any other desired manner.

The pump is provided with an electric solenoid |08, in an electric circuit adapted to be closed 5 so as to energize the solenoid when the contacts H0 are closed by movement of the throttle to a predetermined low or idling load position. When the circuit is closed, the armature ||2 of the solenoid is pulled downwardly from the position shown in the drawings against the action of the retracting spring ||4 and through the medium of the control arm ||6 operates to turn .valve 82 to a position which opens the auxiliary overilowA passage 18. f

In Figs. 6 and 7 a variation has been illustrated in which an auxiliary ,overow valve 82a provides communication between a delivery passage, which may for example be passage 60, and an auxiliary overflow passage 18a which returns fuel from paso sage 60 to the suction line 22 when valve 82a is moved to the position shown in Fig. 7. Evidently, as many outlets may be cut out of action as desired by the employment of auxiliary overflow means of this kind.

In Figs. 8 and 9 there is'shown more or less diagrammatically another form of construction for cutting out the delivery to any desired outlet. In this embodiment the delivery passage, for example passage 60, has interposed therein a 70 piston valve I|8 having two spaced recesses |20 land |22 therein. These recesses are connected by means of an internal passage |24 in the valve and an auxiliary overilow passage 18h communicates with the bore in which the valve member 75 slides. The valve is urged to the position shown in Fig. 8 by a spring |26 and is moved to the position shown in Fig. 9, in the embodiment illustrated, by means of a piston |28 operating in cylinder |30 and loaded by spring |32. Cylinder admission. In the position of the device shown in Fig. 8 is will be evident that delivery will take place through passage 60 since the pressure liquid cannot escape from the recess |22 to which it flows through the valve passage |24. If because of reduced air pressure in the connection |36 and the left hand portion of cylinder |30, due to throttling of the air supply to the engine, piston |28 is moved to the left to shift valve IIB to the position shown in Fig. 9, it will be evident that the delivery passage Bil will be placed in communication with auxiliary ,overilow passage 'iBb by way of recesses |20 and |22 and the valve passage |22, thus operating to cut out of action the outlet to which passage 60 delivers.

It will be evident that any suitable form of control may be used to actuate the different forms of auxiliary overow valve construction described above as, for example, by employing manual control or electric solenoid control for the forms shown vin Figs. 6 lto 9 or employing the vacuum control for the arrangement shown in Fig. 5.

From the foregoing description it will be apparent that the invention may be carried into eiect with numerous different specic forms of apparatus and it is accordingly to be understood as not limited in its scope to the forms herein described and illustrated by way of example, but is to be considered as embracing all forms of apparatus falling within the terms of the appended claims when they are construed as broadly as is consistent with the state of the prior art.

Certain specic features of the pump mecha-.

nism shown but not claimed, in this application, forms the claimed subject matter of my copending application Serial No. 224,211.

What I claim is:

1. A plunger pump constructed to effect delivery from a common chamber to different pump outlets at different times during the delivery stroke of the plunger, and meansselectively operable to conne delivery to less than the total number of said outlets.

2. A plunger pump constructed to effect delivery from a common chamber to different pump outlets at different times during the delivery stroke of the plunger, means for adjusting the pump to vary in like manner the quantities delivered to the several outlets, and means selectively operable independently of the adjusting means to confine delivery to less than the total number of said outlets while permitting delivery to the remainder of quantities .determined by the position of the adjusting means.

3. A plunger pump constructed to effect delivery from a common chamber to ditierent'pump outlets in sequence during the delivery stroke of the plunger, and means selectively operable to confine delivery to a number of outlets less in.

number than the total number and not in immediate sequence.

4. A plunger pump constructed to effect delivery irom a common chamber to dierent pump outlets in sequence during the delivery stroke of the plunger, and means selectively operable t0 confine delivery to every other outlet in the sequence.

5. A plunger pump having a plurality of outlets, means for effecting delivery to different outlets at different delivery periods during the delivery stroke of the plunger, overflow means for determining the times of said delivery periods, and auxiliary overflow means selectively operable to determine the number of ineffectivedelivery periods during the delivery stroke of the plunger,

6. A plunger pump having a plurality of outlets, means for eiecting delivery to dierent outlets at diierent delivery periods during the delivery stroke of the plunger, adjustable overflow means for determining the timing and length of duration of the delivery periods and auxiliary overflow means selectively operable independently of said adjustable overflow. means to determine the number of ineffective delivery periodsduring the delivery stroke of the plunger.

7. A plunger pump including a cylinder having a plurality of longitudinally spaced delivery ports and a plurality of longitudinally spaced overiiow ports, a ported plunger operable to effect delivery through diierent of said delivery ports at different times during the delivery stroke of the plunger, means providing for overflow from the pump, and means for selectively permitting or preventing overflow through the first mentioned means to respectively cut `oi or eiect delivery through certain of said delivery ports.

8. A plunger pump including a cylinder having a plurality of longitudinally spaced delivery ports, a plurality of longitudinally spaced overilow ports and an auxiliary overflow port, a ported plunger operable to effect delivery through diiierent of said delivery ports at different delivery periods during the delivery stroke of the plunger and to eiect overiiow through said overflow ports during the times intervening between the delivery periods, said auxiliary overflow port beinglocated to be in communication with the pump chamber through said ported plunger during the time when delivery is normally effected through at least one of said delivery ports, and a valve for selectively permitting or preventing overflow through said auxiliary overflow port.

9. A plunger pump including a cylinder having a plurality of longitudinally spaced delivery ports, a plurality of longitudinally spaced overilow ports and auxiliary overflow means including a plurality of longitudinally spaced auxiliary overflow ports, a ported plunger operable to effect delivery through dierent delivery ports at diiierent delivery periods during the delivery stroke of the plunger and to eiTect overiiow through said overflow ports during the times intervening between the delivery periods, and valve means for selectively permitting or preventing overflow through said auxiliary overflow ports, said auxiliary overflow ports being located in the cylinder so as to be placed in communication with the pump chamber through the ported plunger only at times when the plunger is in position to effect delivery through non-adjacent delivery ports.

10. A plunger pump including a cylinderhaving a plurality of longitudinally spaced delivery ports each connected to a diierent pump outlet, a ported plunger for placing different ports in communication with the pump chamber at different times during the delivery stroke of the plunger, a plurality of overiiow ports located in the cylinder to determine the time and duration of delivery through said delivery ports, a plurality of auxiliary overflow ports in the cylinder, said auxiliary overflow ports being located so that different ones thereof are placed in communication with the pump chamber by the ported plunger concurrently with dierent delivery ports respectively, and means for selectively preventing cr permitting overiiow through said auX- iliary overflow ports.

1l. A plunger pump including a cylinder having a plurality of longitudinally spaced delivery ports-delivery passages connecting each of said delivery ports to a different pump outlet, certain of said delivery passages having an overiiow passage communicating therewith between the delivery port and the pump outlet, and valve means selectively operable to permit or prevent fiow through said overflow passages.

12. Fuel injection apparatus for multiple cylinder internal combustion engines comprising a pump including a cylinder and a cooperating plunger, a plurality of pump outlets receiving fuel from the pump chamber at different times during the delivery stroke of the plunger and adapted to deliver the fuel to dierent engine cylinders respectively, overflow means for selectively preventing delivery from the pump cylinder to certain of said outlets, and means operable in response to a predetermined condition of engine operation for rendering said overiiow means effective to prevent delivery to said certain of said pump outlets.

13. Fuel injection apparatus for multiple cylinder internal combustion engines comprising a pump including a cylinder and a cooperating plunger, a plurality of pump outlets receiving fuel from the pump chamber at diierent times during the delivery stroke of the plunger and adapted to deliver the fuel to diierent engine cylinders respectively, overflow means for selectively preventing delivery from the pump cylinder to certain of said outlets, and means operable in response to an impulse indicative of predetermined low or idling load operation of the engine for rendering said overflow means eiective to prevent delivery to said certain of said pump outlets.

TORBJRN viK'roR DILLSTRM. 

